Karnataka: New wonders in rivers of Western Ghats

A team of researchers has a discovered a species called Pethia Sahit — a new species of fish from the Western Ghats. The team of researchers include Unmesh Katwate from Bombay Natural History Society, Pradeep Kumkar from Modern College of Arts, Science and Commerce, Pune, Rajeev Raghavan from Kerala University of Fisheries and Ocean Studies, and Neelesh Dahanukar from Indian Institute of Science Education and Research, Pune.

Providing details about the new species Rajeev Raghavan said, “Pethia sahit is described from the Hiranyakeshi, a tributary of the Krishna river in the Western Ghats. The new species is syntopic — and shoals together — with Pethia longicauda, a species found recently from the same river. The common name for the species is Prakash’s Barb named after Prakash Tambe, a local resident, who helped the team in the field surveys leading to the discovery of the new species. The species is found in two localities, Ghatkarwadi and Gavse-Ajara, located in the upstream catchments of the east-flowing Hiranyakeshi in Ajara, Kolhapur District of Maharashtra.”

There are currently 39 valid species in the genus Pethia, of which nine are endemic to peninsular India, and in particular to the river systems originating in the Western Ghats mountain ranges.

Pethia Sahit and Pethia longicauda are distributed in the Krishna river system of the southern India, while their sister taxa Pethia phutunio and Pethia ticto are distributed in Ganges and Mahanadi of northern India. Since all these river systems ultimately go into the Bay of Bengal, there is a possibility that some evolutionarily recent freshwater connections occurred along the coastline of this bay due to high rainfall and vast lowland floodplains.

“Pethia sahit’ is also ecologically fascinating as it coexists syntopically with its congener Pethia longicauda. The unique syntopic bilateral compatibility, where both the species actually shoal together, adds to our knowledge on the behavior of these small cyprinid fishes. Such information can be useful to understand unique trends in evolution,” said Rajeev Raghavan corresponding author of the paper that was published in Zootaxa recently.

‘Neela’ found in Kabini

A team of reasearchers including Ralf Britz from The Natural History Museum, London, V K Anoop from, Kerala University of Fisheries and Ocean Studies (KUFOS), Kochi and Neelesh Dahanukar from Indian Institute of Science Education and Research (IISER), Pune have discovered a new species of badid fish from Western Ghats called Dario Neela. The species name ‘neela’ is derived from the Malayalam word, ‘Nila’, for blue and alludes to the striking iridescent blue colour of males.

Anoop VK, co-author of the study said, “The species has been described from a small tributary stream of the Kabini . It can be distinguished from congeners by the male colouration in life, which shows wide rims of iridescent blue in all median fins and the pelvic fin. The Badidae are a family of small freshwater fishes distributed in waters from Pakistan and India east to Myanmar and Thailand with the Mekong forming the eastern most limit of their distribution.”